Your XML friend XPATH command line xmllint

March 5th, 2011 mysurface Posted in Text Manipulation, xmllint | Hits: 151663 | 10 Comments »

Do you have a large XML to analyze? to query for info? Maybe you are using a XML viewer, a string search for that. But if your XML have a proper structure and you have understand enough for the structure, you may want to consider to use XPATH.

[Q] What is XPATH?
XPath is a “language” for finding information in an XML document. Something like SQL, it has its own syntax to help you to query for your info in an XML. To know more about XPATH, can check out this XPATH tutorial.

[Q] Is there any XPATH command that I can use to query my XML?
xmllint, which comes with libxml2.

xmllint provides you a shell where you can continuously to query your XML.

xmllint --shell myXML.xml

Shell mode is also a good way for you to learn up XPATH, type ‘help’ in the xmllint shell shows you a list of command it support.

Take books.xml sample as example.

To query all the books title, you can do this in the shell.

> cat //title
 -------
<title lang="en">Everyday Italian</title>
 -------
<title lang="en">Harry Potter</title>
 -------
<title lang="en">XQuery Kick Start</title>
 -------
<title lang="en">Learning XML</title>

xmllint shell support grep where you can search with string keywords

> grep XML
/comment() : c--       20
/bookstore/book[4]/title : t--       12 Learning XML

grep in shell is not XPATH syntax, for XPATH to do something similar to grep, you can use contains().

> cat //*[contains(*,"XML")]

XPATH supports many functions to enlighten your query.

[Q] I wanna use the XPATH result for further manipulation, can I get it with xmllint?
--xpath option.

You can do this.

xmllint --xpath //title books.xml

And.... xmllint can do more than that.

I hope you enjoy reading this, bye.

10 Responses to “Your XML friend XPATH command line xmllint”

  1. Interesting justification. I really like to read it Martha

  2. nice post

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  4. Thanks this is exactly what I needed.

    I googled for XPath tools and got a lot of fancy online and offline apps, some fancy looking Firefox plugins (which all crashed) and finally found this post!

    xmllint is unbeatale when it comes to simplicity & ease of use.

    Thanks again!

  5. I’ve primarily been using xmllint for formatting XML documents, but had no idea you could parse XML documents and later issue XPath commands. Until now, I was pretty much using XML Copy Editor to issue XPath commands.
    Thank you very much for this!!!

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  7. Beats vim. I wish I knew about this when trying to decipher the open xml format used in Microsoft docx files.

  8. Xpath is not working, is there anything needed to install xpath

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  10. The problem is that 99.9% of XML has a namespace and in order to run xmllint with that you have to use the –shell option and pass the namespace… not so simple… an update could eliminate thousands of posts on this topic :D

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